Hey gang, I took the Civic to Buttonwillow and ran into very serious braking problems, and I was hoping someone could shed some light. It's a stock Civic Si, with the only changes being a rear bar, 225 RE71R and at the time, Project Mu Club Racer brake pads, that were recommended to me for track work by several people.

After 6 laps around Buttonwillow, the brake pedal felt increasingly bad, until on the cool down lap, I lost all braking except with the handbrake. My front pads and rotors looked like this:

These pads and rotors had approximately 500 street miles and an autocross on them before this happened. I was able to limp the car to Autozone, buy AZ replacement rotors and grind the pads down until they were level and free of grooving. I go back out the next session and it happened again to the new AZ rotors. I thought the pads might have been defective, so I actually had a backup pair of brand new Club Racer pads, which I paired with OEM Honda rotors, and the next session out, same exact result. I swapped on OEM Honda pads with an OE replacement rotor, no scoring/grooving, but had pad fade, so that was annoying. This ended my day since I was out of brakes at this point. I've since swapped on some EBC Yellows and Centric "High Carbon" premium rotors, but I'm done tracking this car since this is both very dangerous and very expensive to go through brakes so fast.

Brake fluid was freshly flushed with Castrol SRF, and calipers were inspected and are leak free, and do not seem to be sticking or dragging the pads at all. For the past 82,xxx miles the car has never had a problem on street, in the canyons or at Autocross with it's braking performance, so very confused what's going on here. As per Google, no one else seems to have issues with braking in regards to my chassis or these brake pads, which I've been assured are a very high quality pad. Any ideas?

Just a wild guess, but I think your brakes didn't have sufficient cooling. Either the brakes were too small or not enough air was being channeled to the brakes. I suspect this because the edges along the brake pad seem like they chipped away. Does the rotor look blue anywhere? Maybe some black spots as well?

May seem like a dumb question but how were you lapping the car? I destroyed my OEM S2000 brakes because I wasn't taking cool down laps. When I swapped to the Pmu CR's I had no problem running 3-4 flat out laps but then took a cool down lap to help manage the heat.

I'd second looking into adding some ducts as well to help get some more cool air over the brakes.

Tracked the Integra ('91 GS) once at Holtville... on the third lap, I had zero brakes at the end of back straight... Thank God, going straight there, meant you just kept going down the runway....

They didn't feel right in the two proceeding corners... but my inexperience (1st ever track track day) I wrote those two corners off as increased speed being scrubbed off, as I was learning the course, and feeling more comfortable at the 100+ speeds I was reaching, and waiting longer to apply the brakes.

Putzed the 1/2 lap back to where we had our impromptu pit on the front straight... put a pyrometer on the front rotors, the were over 1000 deg. Not sure exactly how hot they were... as we watched the digital readout go up... it error-ed out on the 4th digit, since it only had three digit's...

Speaking of such, that very Miata... is currently listed on this site for sale!

...and the experience at Holtville that day, set in motion eventually getting a Miata myself.

That totally stock Miata (on Victoracers), ran for hours on end... with the only cool down being the couple of minute of banter while switching drivers every 10 laps or so, and one fuel refill from a 2.5G can near the end of the day.